Fly fishing line with water-repellent preservative dressing



A. M. HOWALD Aug. 4, 1970 FLY FISHING LINE WITH WATER-REPELLENTPRESERVATIVE DRESSING Filed Feb. 5, 1968 Fl GI JNVENTOR. ARTHUR M HOWALDUnited States Patent Ofice 3,523,034 Patented Aug. 4, 1970 US. Cl.117-76 3 Claims ABSTRACT OF THE DISCLOSURE A fly fishing line having asurface layer of plasticized polyvinyl chloride, and a water-repellentpreservative dressing on the surface layer, consisting essentially of aprimary plasticizer for the polyvinyl chloride, parafiin wax and a metalsoap of the class consisting of aluminum, calcium and magnesium soaps toinhibit crystallization of the paraffin wax.

BACKGROUND OF THE INVENTION This invention relates to a fly fishing linehaving a surface layer of plasticized polyvinyl chloride, and a dressingon the surface layer which preserves the flexibility of the line andwhich is water-repellent so as to cause the line to float lightly uponthe surface of the Water.

A known type of fly fishing line consists of a filamentous coresurrounded by a flexible surface layer of plasticized polyvinylchloride. Such a fly fishing line is customarily produced by coating abraided nylon core with a surface layer consisting of a polyvinylchloride plastisol. A polyvinyl chloride plastisol consists essentiallyof a suspension of finely divided polyvinyl chloride in a liquid phasethat is made up of one or more plasticizers. The final step in themanufacture of such a line consists in heating to a temperature of350380 F. When a polyvinyl chloride plastisol is heated to such atemperature, the polymer fuses and goes into solution in the plasticizerphase. The resulting solution of the polymer in the plasticizer, uponcooling, is no longer a liquid, but is a flexible solid surface layersurrounding the braided nylon core.

In order to obtain a fly fishing line of the required low density, ithas been found to be necessary to incorporate in the plastisolingredients which cause the surface layer of plasticized polyvinylchloride in the final product to be cellular in character. Methods ofproducing a fly fishing line having a cellular surface layer ofplasticized polyvinyl chloride are disclosed in US. Pat. Nos. 2,862,282and 3,043,045.

Pat. No. 3,043,045 states that a fishing line produced by the methoddisclosed in that patent floats upon the water without any surfacedressing. A line produced by that method may have a specific gravity ofabout 0.95. However, the mere fact that a fly fishing line has aspecific gravity of 0.95 does not provide suflicient buoyancy to givesatisfactory results. Such a line, unless it has a water-repellentsurface, will float partially submerged.

A fly fishing line, in order to give satisfactory results, must have ahighly water-repellent surface so that it floats lightly on the surfaceof the water, supported by the surface tension, so as to enable thefisherman to pick the line cleanly oil the water whenever a new cast isto be made.

The difliculty of securing proper flotation of a fly fishing line isincreased by reason of the fact that the line must have sufiicientweight per foot to permit the fisherman to cast the fly through thedesired distance, since the weight of the fly itself may be regarded asnegligible. Even in the case of a line having a density that isapproximately equal to or slightly less than that of water, the linemust be of substantial diameter in order that it may have sufficientweight per foot to permit the line to be cast. The substantial diameterof the line results in a substantial area of contact between the lineand the water on which the line is floating, and this substantial areaof contact increases the tendency of the line to carry an excessiveamount of water when the fisherman picks the line off the surface of thewater in order to make a new cast. It has been found that a fly fishingline having a surface layer of plasticized polyvinyl chloride tends tostiffen with age. Such stiflening is due to gradual loss of theplasticizers, which have some degree of volatility and are to someextent extracted by water. The stiffening of a fly fishing line withage, like the tendency of a line to carry an excessive amount of waterwhen the fisherman picks the line off the surface of the water to make anew cast, will interfere with the action of the line in casting, andwill make it more difficult to cast the line so as to drop the fly atthe desired spot on the surface of the water.

SUMMARY OF THE INVENTION The principal object of the invention is toprovide a novel dressing which, when applied to a fly fishing linehaving a surface layer of plasticized polyvinyl chloride, substantiallyincreases the water-repellency of the surface and also preserves theline against stiffening with age. More specific objects and advantagesare apparent from the following detailed description, which is intendedto disclose and illustrate but not to limit the invention.

A fly fishing line having a surface layer of plasticized polyvinylchloride possesses a substantial degree of waterrepellency, and Pat. No.3,043,045 states that a fly fishing line having a surface layer ofcellular plasticized polyvinyl chloride produced by the method describedin that patent does not require any surface dressing. Of course thewater-repellency of a fly fishing line having a surface layer ofplasticized polyvinyl chloride will not be improved by the applicationof a dressing unless the waterrepellency of the dressing is appreciablygreater than the water-repellency of the untreated surface layer. Thepresent invention is based upon the discovery that the water-repellencyof any fly fishing line having a surface layer of plasticized polyvinylchloride can be improved substantially, so as to improve the resultsobtained when the line is used in fly fishing, by applying to the line adressing consisting essentially of a primary plasticizer for thepolyvinyl chloride, paraflin wax, and an aluminum, calcium or magnesiumsoap, and upon the further discovery that such a dressing preserves theline against stiffening with age.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 of the drawing is a longitudinalsection, on an enlarged scale, of a fly fishing line embodying theinvention.

FIG. 2 is a transverse section on the line 22 of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS sist of nylon, Dacron (apolyester), silk or any other suitable filamentous material. When thecore has substantially greater total tensile strength and substantiallyless elongation than the surface layer of the line, it is the core whichdetermines the tensile strength of the line, as well as the degree towhich the line will stretch or elongate, because under a tensile loadthe surface layer tends to longate freely and thus permits the core totake the load. Under such circumstances, the elongation orstretch-ability of the line is substantially that of the core, and thetensile strength of the line is substantially equal to that of the core.In that way, the core prevents the line from being excessively softunder tension, so as to enable the fisherman to set the hook by a jerkon the line after a fish has taken the fly.

Although the core may determine the tensile strength and elongation ofthe line, the core alone, before the addition of the surface layer, ismuch more flexible than is desirable in a fly fishing line. Thenecessary critical degree of flexibility is imparted to the present flyfishing line by the surface layer surrounding the core.

When the core consists of a monofilament of nylon having a diameter morethan about 0.12 inch, it is desirable that the nylon be a modified nylonof the type known as limp nylon which is sufliciently flexible so thatthe overall stiffness of the line will not be excessive.

Ordinarily the core is a multi-filament core, which is substantiallymore flexible than a monofilament core.

non-viscous liquid which flows freely so as to wet the core thoroughly.The primer may consist of a solution of any synthetic resin that iscompatible with the plastisol which is to be applied as the surfacelayer. For example, the primer may consist of a solution of a copolymerof vinyl chloride and vinyl acetate in methyl isobutyl ketone. Anotherprimer which may be employed is an acrylonitrile-butadiene copolymersolution in methyl ethyl ketone or methyl isobutyl ketone.

If desired, the primer solution may be applied while hot, in order toincrease the solubility of the synthetic resin in the solvent employed.The primer may be applied to the core in a continuous operation, bypassing the core continuously through a tank of the primer and thenexposing the core to radiant heat or to circulated hot air in order toevaporate the solvent from the primer and to remove moisture from thecore.

After the core has been coated with a primer and dried, the surfacelayer is applied to the core in the form of a plastisol. The polymer inthe plastisol used in the practice of the invention consists essentiallyof polymerized vinyl chloride, but the vinyl chloride used to form thepolymer may be copolymerized with small proportions of other monomers,e.'g., with a proportion of vinyl acetate equal to about one half of onepercent of the weight of the vinyl chloride used. For example 96% of thevinyl chloride may be present in the form of a homopolymer, and theother 4% of the vinyl chloride may be present in the form of a copolymerobtained by the copolymerization of 4 parts of vinyl acetate with 35parts of vinyl chloride, the copolymer being dissolved in theplasticizer in which the fine particles of the homopolymer are suspendedto form the plastisol.

A polymer for use in the plastisol may be prepared by emulsionpolymerization. Preferably the polymer is in the form of a powder havinga particle size of the order of one micron, which may be mixed with oneor more plasticizers to produce a plastisol.

The plasticizers which may be employed include all of the plasticizerswhich are useful in the production of flexible po yvinyl chlorideproducts. These known plasticizers 4 include di-octylad-ipate,di-Z-ethylhexyl phthalate, dicapryl phthalate, tricresyl phosphate andtrioctyl phosphate.

Minor proportions of resin-type plasticizers also may be added toincrease the viscosity of the plastisol and to obtain the desiredproperties in the finished product.

The proportion of plasticizers in the plastisol depends upon theparticular plasticizers and the particular polymer used, and may varyfrom about 30 to about 70 parts of platsicizers to parts of polyvinylchloride.

In accordance with usual practice, the plastisol should contain fromabout one to about four parts of a stabilizer for each 100 parts ofpolyvinyl chloride. The stabilizer may be a substance which combineswith hydrogen chloride liberated from the polyvinyl chloride, such as alead soap. Other stabilizers which may be employed include soaps of zincand cadmium, and epoxides.

Other modifiers, such as pigments or dyes, may be added in smallproportions if desired, without affecting the quality of the finalproduct.

The specific gravity of plasticized polyvinyl chloride is from about 1.2to about 1.3. Therefore, in the production of a fly fishing line inwhich the surface layer consists of pl'asticized polyvinyl chloride, itis customary to reduce the specific gravity of the surface layer byforming gas bubbles in the surface layer or by incorporating hollowmicrospheres in the surface layer in order to produce a more buoyantline.

A cellular surface layer may be produced by incorporating in theplastisol a conventional blowing agent, as described in US. Pat. No.2,862,282. During the fusing operation the blowing agent decomposes toliberate a gas such as nitrogen. The blowing agent is dispersed in theplastisol in the form of fine particles, so that in the finished producta gas bubble may be present in the vicinity of each particle, althoughthe gas bubbles generated by a number of particles may merge to form asingle gas bubble. In this way it is possible to produce a fly fishingline having an average specific gravity less than 1.0.

Another method of producing a fly fishing line which has reducedspecific gravity consists in incorporation in the plastisol, before theplastisol is applied to the core, of hollow microspheres such as glassmicroballoons, as described in US. Pat. No. 3,043,045.

The glass microballoons may be produced as described in US. Patents Nos.2,978,339 and 2,978,340. The composition of the glass preferablyconsists of oxides of an alkali metal and silica, together with smallproportions of other oxides, such as an oxide of boron. The molarproportion of silica in the glass preferably is greater than the molarproportion of sodium or other alkali metal, and preferably is at leastthree times as great.

The diameter of the glass microballoons may be of the order of 10 to 270microns and the average diameter may be of the order of 100 microns. Thewall thickness of the microballoons is of the order of one percent ofthe diameter.

The proportion of glass microballoons to be dispersed in the plastisoldepends upon the initial density of the plastisol and upon the finaldensity desired. Usually the specific gravity of the plastisol is about1.2 to 1.3, so that the incorporation of 10-11% by weight of the glassmicroballoons in the plastisol will bring the specific gravity of thecomposition to about 0.95.

A braided nylon core usually is hollow in form and therefore contributesto the buoyancy of the line.

The fly fishing line of the present invention may be produced from acore and a plastisol by means of the apparatus disclosed in US. Pat. No.2,862,282. In the operation of that apparatus, the core which has beencoated with a primer is passed continuously through a tank containingthe plastisol. The core, which becomes coated with a relatively thicklayer of the plastisol, is drawn vertically out of the plastisol, andpasses through an opening formed at the line of contact of two rollerswhich have circumferential grooves that register to form a passagebetween the two rollers at the line of contact. In that apparatus, thesize of the opening or passage between the rollers at the line ofcontact may be varied gradually as the operation proceeds. The diameterof the finished product is determined by the diameter of the openingthrough which the coated core is drawn between the rollers. In order toproduce a tapered fly fishing line embodying the invention, the diameterof the opening between the rollers is varied gradually as the coatedcore passes between the rollers, thus varying the thickness of the layerof plastisol surrounding the core so as to provide the desired taper.

Preferably the diameter of the core itself is uniform throughout thelength of the line.

A line which has been prepared by the procedure hereinbefore describedis in its final form, except that the surface layer consists of arelatively soft plastisol. In order to harden the surface layer, theline is then heated to a temperature between 350 and 380 F., preferablyby passing the coated core continuously through an oven in which it issubjected to radiant heat.

During this heating operation, the polyvinyl chloride is fused so as toconvert the plastisol to a solution of the polyvinyl chloride in theplasticizers. The length of time during which the line is held at atemperature between 350 and 380 F., may vary from /2 to minutes,depending upon the exact temperature used.

The final step in producing a fiy fishing line embodying the presentinvention consists in coating the surface of the line with a dressingconsisting essentially of a primary plasticizer for the polyvinylchloride, parafiin Wax and a metal soap of the class consisting ofaluminum, calcium and magnesium soaps.

The ingredient in the dressing of the present invention which isresponsible for substantially increasing the waterrepellency of thesurface of the line is the parafiin wax. However, parafiin waxordinarily forms large crystals, which would tend to flake off the lineand would make it virtually impossible to apply a coating ofsatisfactory uniformity. This difliculty is overcome in the practice ofthe present invention by incorporating a metal soap in the dressing toinhibit crystallization of the paraffin wax.

Another essential ingredient in the dressing of the present invention isa substance which is a plasticizer for the polyvinyl chloride. It hasbeen found that such a substance, when present in the dressing,preserves the plasticized polyvinyl chloride against stiffening withage, by counteracting loss of plasticizer from the plasticized polyvinylchloride. This substance in the dressing also performs the function ofthinning the paraffin wax to a consistency such that the dressing can beapplied without difi'iculty. A thinner of solvent which is not a primaryplasticizer for the polyvinyl chloride cannot be used as the solethinner in the dressing, because such a substance would extractplasticizer from the plasticized polyvinyl chloride and thus cause rapiddeterioration of the fishing line.

Thus the dressing of the present invention consists essentially of aprimary plasticizer for the polyvinyl chloride, paraffin wax and a metalsoap of the class consisting of aluminum, calcium and magnesium soaps.At least 50% by weight of the thinners or diluents for the parafiin waxin the composition should consist of a primary plasticizer or primaryplasticizers for the polyvinyl chloride in the surface layer of thefishing line, so that loss of plasticizer from the plasticized polyvinylchloride in the surface layer of the fishing line will be counteractedrather than accelerated by the dressing. However, a diluent or solventwhich is substantially more volatile than the primary plasticizer in thedressing can be incorporated in the dressing in a larger proportion,because such a diluent or solvent disappears from the coating before itcan extract plasticizer from the surface layer of the fishing line andtherefore is not a material component of the dressing.

For example, the dressing may contain approximately 1% by weight ofanother water-repellent substance, such 6 as a fluoro grease or oil, asilicone grease or oil, or finely divided Teflon.

The primary plasticizer in the dressing of the present invention may beany of the known primary plasticizers for polyvinyl chloride, or amixture of such substances. Such substances have low volatility, andthus remain in the coating indefinitely and continue to counteract lossof plasticizer from the surface layer of the fishing line. Suchsubstances include di-2-ethyl-hexyl phthalate, di-2- ethyl-hexylsebacate, di-2-ethyl-hexyl azelate, diisooctyl phthalate, diisooctylazelate, diisodecyl phthalate, ditridecyl phthalate, dicapryl phthalate,dioctyl adipate, dihexyl azelate, tricresyl phosphate, triphenylphosphate, cresyldiphenyl phosphate, trioctyltrimellitate and octyldecyl adipate. Such substances are substantially non-volatile esterswhich are compatible with polyvinyl chloride.

Other diluents or solvents which may be present in the dressing in minorproportions include kerosene, highboiling petroleum fractions, andvarious substances which are used as secondary plasticizers forpolyvinyl chloride, such as chlorinated paraffins and chlorinatednaphthalenes.

The amount of the primary plasticizer in the present dressing may rangefrom one half to twice the weight of the parafiin wax.

Paratfin wax is unique in its ability to increase substantially thewater-repellency of the plasticized polyvinyl chloride surface layer.Any available parafiin wax may be used in the dressing of the presentinvention.

The soap which is used in the dressing of the present invention toinhibit crystallization of the paraflin wax may be any soap of aluminum,calcium or magnesium, or a mixture of such soaps. A soap is consideredto be a salt of a saturated or unsaturated fatty acid having at leastseven carbon atoms, such as a stear'ate, oleate, or palmitate. The soapsinclude salts in which the fatty acid is less than the full equivalentamount, so that the molecules consist of hydroxy radicals as well asfatty acid radicals attached to the metal atoms. An example of a mixturewhich can be used is napalm, which is a soap whose molecules contain anaverage of two fatty acid radicals and one hydroxy radical for eachaluminum atom, the fatty acid radicals being a mixture of oleic,naphthenic and palmitic acid radicals. The preferred soaps for use inthe practice of the invention are aluminum soaps, such as aluminumstearate.

The amount of the soap in the present dressing is simply an amount whichinhibits crystallization of the paraffin wax, and may range from 5% to30% of the weight of the parafiin wax.

In the preparation of the dressing of the present invention, the soapand the plasticizer are readily dissolved in the molten paraffin wax ata temperature of about F. While still Warm, the dressing may be appliedto the fishing line by any desired method, for example by passing theline continuously through a tank of the dressing and wiping the surplusdressing from the surface of the line. The dressing also may be appliedby means of brushes or felt pads which have been moistened with thedressing, or may be applied with the fingers while fishing. An extremelythin coating of the dressing on the fishing line is sufficient.

The drawing shows a finished product embodying the invention, in which abraided core 11 composed of a multiplicity of filaments is coated with athin layer of a primer 12 which forms the boundary between the core 11and the surface layer 13. Microballoons 14 are dispersed throughout thesurface layer, and the surface layer is coated with a thin film of adressing 15.

A typical core 11 consists of a braided nylon core having a diameter of.025 inch and a total breaking strength of 15 pounds. If a line ofhigher tensile strength is desired, a core having a total breakingstrength of 20 to 25 pounds may be used.

A typical surface layer 13 has the following composition in parts byweight:

Parts Polyvinyl chloride '(Geon 121) 100 Dioctyl adipate 3 Epoxidizedtall oil (Flexol E P8) 10 Lead soap 3 In addition to the aboveingredients, a typical surface layer has dispersed therein glassmicroballoons having an average diameter of about 100 microns, whichmake up about 30% of the volume of the surface layer.

A typical dressing embodying the present invention consists of 10 partsby weight of parafiin wax, 2 parts of aluminum stearate and 10 parts ofdi-Z-ethyl-hexyl sebacate. A dressing having this typical compositionwas tested by immersing, in a container filled with the dressing, apiece of line several inches long which had an initial diameter between.047 and .048 inch and which had the typical composition and structureabove described. After one week of immersion in the dressing, the linewas found to have become more flexible and to have increased in diameterto .050 inch.

In another experiment, a similar sample of the same line was immersed ina container filled with a dressing which was identical with the dressingused in the previous experiment except that the dressing contained only7.5 parts of di-Z-ethyl-hexyl sebacate, with the addition of 2.5 partsof kerosene. In this experiment, the sample of line was found to beunchanged after one weeks immersion.

In a control experiment, a similar sample of the same line was immersedin a container filled with a liquid which was identical with thedressing used in the first experiment except that it contained 10 partsof kerosene instead of 10 parts of di-Z-ethyI-hexyl phthalate. In thisexperiment, the sample of line after one weeks immersion was found toh-ave stiffened substantially, and to be only .045 inch in diameter.

In the first experiment, the surface layer gained plasticizer; in thethird experiment plastizer was extracted from the surface layer; and inthe second experiment the surface layer remained unchanged.

If the line coated with the dressing of the present invention is to bekept in a sealed container, it may be desirable to use a dressing havinga composition similar to that of the dressing employed in the secondexperiment, in order to prevent an undesirable reduction in thestiffness of the line. However, under ordinary conditions, when the lineis exposed to the atmosphere, it is not necessary to use any diluent inthe dressing other than the primary plasticizer, and the dressing usedin the first experiment gives excellent results, with no decrease instiffness.

I claim:

1. In a fly fishing line the surface of which consists essentially ofplasticized polyvinyl chloride wherein the improvement comprises awater-repellent preservative dressing on the surface of the line,consisting essentially of one part by weight of parafiin Wax, a thinnerfor the paraffin wax, at least by weight of the thinner consisting ofone-half to two parts of at least one substantially non-volatile esterwhich is a primary plasticizer for polyvinyl chloride, and .05 to 0.3part of a metal soap of the class consisting of aluminum, calcium andmagnesium soaps to inhibit crystallization of the paraflin wax.

2. A fly fishing line according to claim 1 wherein the metal soap is analuminum soap.

3. A fly fishing line according to claim 1 wherein the dressingadditionally includes a minor proportion of a secondary plasticizer toprevent the primary plasticizer from softening the line.

References Cited UNITED STATES PATENTS 2,215,760 9/1940 Ledrich 4344.98X 2,223,158 11/1940 Licata et al.

2,603,576 7/1952 Cook et a1.

2,748,525 6/1956 Volz 43-4498 2,862,282 12/1958 Beebe 161-175 X3,043,045 7/ 1962 Martuch 43-4498 WILLIAM D. MARTIN, Primary ExaminerRALPH HUSACK, Assistant Examiner US. Cl. X.R.

